1. Field of the Invention
The present invention relates to a piezoelectric vibration module and a vibration generating apparatus including the same.
2. Description of the Related Art
A vibration generating apparatus, a component converting electrical energy into mechanical vibrations through the generation of electromagnetic force, is commonly mounted in a mobile phone to be used to silently notify a user of call reception by transferring vibrations thereto.
Meanwhile, in accordance with rapid growth in the mobile phone market and the trend for adding functionality to mobile phones, mobile phone components having a compact size and a high degree of quality have been required. In this situation, the demand for the development of a vibration generating apparatus having a novel structure capable of overcoming the disadvantages of existing vibration generating apparatuses, and having significantly improved quality with respect thereto, has increased.
In addition, as the release of smartphones has rapidly increased, a touchscreen scheme has been adopted therein, such that in addition to silently notifying a user of call reception, vibration generating apparatuses have been used in order to generate vibrations when the touchscreen is touched.
Degrees of performance required of the vibrations generated when the touchscreen is touched in particular, are as follows. First, since vibrations are generated more frequently in devices having touchscreens than in phones merely vibrating at the time of call reception, an operational lifespan of a vibration generating apparatus should be increased. Second, in order to improve user satisfaction when a user is provided with vibrations when the touchscreen is touched, a vibration response speed should be increased, in accordance with a speed at which the screen is touched.
In accordance to the demand for an increased operational lifespan and improved response times as described above, a linear vibrator has been currently used in the mobile phone including a touch screen.
The linear vibrator may linearly resonance-move a mover suspended from a spring due to electromagnetic force generated between a coil and a magnet using a mass body connected to an elastic member installed in the vibrator rather than using a principle of rotation of a motor to generate vibrations.
Alternatively, the linear vibrator may linearly resonance-move a mover through contraction and expansion of a piezoelectric element using the piezoelectric element as an actuator to generate vibrations.
Particularly, a vibration generating apparatus using the piezoelectric element is deformed when the piezoelectric element has power applied thereto. However, since a degree of deformation of the piezoelectric element is significantly low, it may be very difficult to utilize this deformation for vibrations.